2.65a on Mac OsX Mountain Lion Problem

Hello,

I’m new to Blender and am having problems with 2.65a on Mac OS-X Mountain Lion. I’m using a MacBook Pro 15" Retina.

The main problem seems to be that I cannot select vertices, edges or faces on mesh objects. The software insists on extruding all elements equally. A standard cube become as a huge cube. A sphere becomes a huge sphere and the plane…well, guess.

It also leaves an image of the original in-situ that is not editable.

Has anyone else been having these problems? Being a newbie to this version, there may be settings that I need to tweak that I have no idea about.

Thanks.